/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
package org.apache.directory.server.core.authz.support;
import java.util.ArrayList;
import org.apache.directory.server.core.api.CoreSession;
import org.apache.directory.server.core.api.event.Evaluator;
import org.apache.directory.server.core.api.event.ExpressionEvaluator;
import org.apache.directory.server.core.api.interceptor.context.LookupOperationContext;
import org.apache.directory.server.core.api.subtree.SubtreeEvaluator;
import org.apache.directory.server.core.api.subtree.RefinementEvaluator;
import org.apache.directory.server.core.api.subtree.RefinementLeafEvaluator;
import org.apache.directory.shared.ldap.aci.ACITuple;
import org.apache.directory.shared.ldap.model.constants.SchemaConstants;
import org.apache.directory.shared.ldap.model.entry.Entry;
import org.apache.directory.shared.ldap.model.exception.LdapException;
import org.apache.directory.shared.ldap.model.exception.LdapNoPermissionException;
import org.apache.directory.shared.ldap.model.schema.SchemaManager;
/**
* An implementation of Access Control Decision Function (18.8, X.501).
* <br/>
* This engine simply filters the collection of tuples using the following
* {@link ACITupleFilter}s sequentially:
* <ol>
* <li>{@link RelatedUserClassFilter}</li>
* <li>{@link RelatedProtectedItemFilter}</li>
* <li>{@link MaxValueCountFilter}</li>
* <li>{@link MaxImmSubFilter}</li>
* <li>{@link RestrictedByFilter}</li>
* <li>{@link MicroOperationFilter}</li>
* <li>{@link HighestPrecedenceFilter}</li>
* <li>{@link MostSpecificUserClassFilter}</li>
* <li>{@link MostSpecificProtectedItemFilter}</li>
* </ol>
* <br/>
* Operation is determined to be permitted if and only if there is at least one
* tuple left and all of them grants the access. (18.8.4. X.501)
*
* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
*/
public class ACDFEngine
{
private final ACITupleFilter[] filters;
/**
* Creates a new instance.
*
* @param schemaManager The server schemaManager
*
* @throws LdapException if failed to initialize internal components
*/
public ACDFEngine( SchemaManager schemaManager )
{
Evaluator entryEvaluator = new ExpressionEvaluator( schemaManager );
SubtreeEvaluator subtreeEvaluator = new SubtreeEvaluator( schemaManager );
RefinementEvaluator refinementEvaluator = new RefinementEvaluator( new RefinementLeafEvaluator( schemaManager ) );
filters = new ACITupleFilter[]
{
new RelatedUserClassFilter( subtreeEvaluator ),
new RelatedProtectedItemFilter( refinementEvaluator, entryEvaluator, schemaManager ),
new MaxValueCountFilter(),
new MaxImmSubFilter( schemaManager ),
new RestrictedByFilter(),
new MicroOperationFilter(),
new HighestPrecedenceFilter(),
new MostSpecificUserClassFilter(),
new MostSpecificProtectedItemFilter() };
}
/**
* Checks the user with the specified name can access the specified resource
* (entry, attribute type, or attribute value) and throws {@link LdapNoPermissionException}
* if the user doesn't have any permission to perform the specified grants.
*
* @param aciContext the container for ACI items
* @throws LdapException if failed to evaluate ACI items
*/
public void checkPermission( AciContext aciContext ) throws LdapException
{
if ( !hasPermission( aciContext ) )
{
throw new LdapNoPermissionException();
}
}
/**
* Returns <tt>true</tt> if the user with the specified name can access the specified resource
* (entry, attribute type, or attribute value) and throws {@link org.apache.directory.shared.ldap.model.exception.LdapNoPermissionException}
* if the user doesn't have any permission to perform the specified grants.
*
* @param aciContext the container for ACI items
* @throws org.apache.directory.shared.ldap.model.exception.LdapException if failed to evaluate ACI items
*/
public boolean hasPermission( AciContext aciContext ) throws LdapException
{
if ( aciContext.getEntryDn() == null )
{
throw new IllegalArgumentException( "entryName" );
}
CoreSession session = aciContext.getOperationContext().getSession();
LookupOperationContext lookupContext = new LookupOperationContext( session, aciContext.getUserDn(),
SchemaConstants.ALL_ATTRIBUTES_ARRAY );
Entry userEntry = session.getDirectoryService().getPartitionNexus().lookup( lookupContext );
// Determine the scope of the requested operation.
OperationScope scope;
if ( aciContext.getAttributeType() == null )
{
scope = OperationScope.ENTRY;
}
else if ( aciContext.getAttrValue() == null )
{
scope = OperationScope.ATTRIBUTE_TYPE;
}
else
{
scope = OperationScope.ATTRIBUTE_TYPE_AND_VALUE;
}
// Clone aciTuples in case it is unmodifiable.
aciContext.setAciTuples( new ArrayList<ACITuple>( aciContext.getAciTuples() ) );
// Filter unrelated and invalid tuples
for ( ACITupleFilter filter : filters )
{
if ( aciContext.getAciTuples().size() == 0 )
{
// No need to continue filtering
return false;
}
aciContext.setAciTuples( filter.filter( aciContext, scope, userEntry ) );
}
// Deny access if no tuples left.
if ( aciContext.getAciTuples().size() == 0 )
{
return false;
}
// Grant access if and only if one or more tuples remain and
// all grant access. Otherwise deny access.
for ( ACITuple tuple : aciContext.getAciTuples() )
{
if ( !tuple.isGrant() )
{
return false;
}
}
return true;
}
}